In 2014, I wrote an article for a scientific writing class about a weird problem I’d become aware of: The lack of fire in our forests. The current wildfires are not the solution that I was looking for. Do you want to find out why our fire control has caused such problems? Do you want to know why we’re having such trouble controlling the fires now? Read on to find out.
A picture of the Walland fire taken just outside Maryville. This is also a good example of wildland-urban interface (discussed later).
Smokey the Bear has a secret identity. By day, he tells us “Only you can prevent wildfires!” By night, he sneaks out deep into the woods of the Smoky Mountains and lights fires.
Smokey doesn’t actually do that. But the United States Forest Service, which he represents, does. The Forest Service tries to stop forest fires, but it also occasionally starts forest fires. It stops some forests from burning, but intentionally burns others. This is especially confusing because, for the first 60-70 years of its existence, it mercilessly stomped out every forest fire that sprang up.
The change in the Forest Service’s policies happened because the Forest Service finally recognized something that scientists had been saying for years: forest fires are an important part of forest ecosystems. According to Dr. Henri Grissino-Mayer, a Professor of Geography at the University of Tennessee at Knoxville, “[forest fires] have been a part of every ecosystem since there’s been fuel to burn.” Dr. Chris Underwood, an assistant professor of geography and a research associate at the University of Wisconsin-Platteville, who wrote his doctoral dissertation on the fire history of the Smokies, says that the Smokies have burned every five to seven years for thousands and thousands of years.
Fires are as natural a part of forest ecosystems as are trees. They seem destructive, and they are destructive. Plants are incinerated by forest fires. Animals flee in terror from forest fires. Our houses burn down in forest fires. For a long time, we assumed that, because they were destructive, they needed to be stopped, so we stopped them with the best of intentions.
Just because forest fires destroy, doesn’t mean they aren’t essential. Ecosystems are too complicated for there to be a one-to-one correlation between destructive and bad. Consider wolves. Wolves, like forest fires, destroy. They kill deer and other peaceful herbivores. Those herbivores were not driven to extinction by predation; they adapted to the destruction wrought by wolves. They reproduce fast enough to maintain stable populations even in the face of predation. Then humans, with the best of intentions, exterminated large predators across most of America, assuming that since they were destructive, they were bad. Now deer are so populous that they threaten to eat many native plants to extinction. Wolves were destructive, but by holding deer populations in check, they prevented even greater destruction.
The situation in forests is similar, if vastly more complicated and subtle. Importantly, forest fires in an undisturbed ecosystem don’t usually destroy trees. Grissino-Mayer says that, prior to 1880, fires were primarily low intensity. They happened every 6-7 years, and they didn’t burn many trees. They burned the understory–the debris on the forest floor and the smaller plants and shrubs—thus rejuvenating the soil for new plants to grow. The trees that did burn, according to Underwood, were less fire-tolerant trees like eastern white pines and red maples: trees which prefer and are more common in wetter, less fire-prone environments. Regular fires kept such trees out of the region and let more fire-tolerant species remain dominant. The destruction fire wrought protected other species, just like wolves protected native plants by killing deer.
Forest fires are not merely wolves that keep the populations of some species from becoming unwieldy; they have other ecological roles. Grissino-Mayer emphasizes that fires recycle nutrients. The burnt remains of the forest understory make surprisingly good soil. As a result, he says, “A lot of trees and other plant species have actually adapted quite readily to repeated fires.” Many plants, he says, are so well adapted to regular wildfires that they can’t reproduce without them, as if deer only reproduced right after being chased by a wolf.
The yellow pines, which include the table mountain pine (pictured above), the Virginia pine, and the shortleaf pine, are such plants. According to Underwood, they have cones that only open and drop their seeds in intense heat. Further, their seeds can only grow if they land in rich mineral soil, such as the soil created by a fire. If there are no fires, their cones won’t open and their seeds won’t drop. Even if the cones do open—perhaps on a hot summer day—the seeds will land on a layer of leaf litter instead of the mineral soil they need.
According to Grissino-Mayer, we’ve been excluding fire from the eastern United States for 80 years. For obvious reasons, the yellow pines have been struggling. At least one of the yellow pines is essentially hopeless, according to Grissino-Mayer. He says, “We’re going to lose table mountain pine because we’ve taken fires out of the forest.” But most of the yellow pines are suffering. For one, they can’t reproduce—at least not effectively—because we’ve excluded fire from the forests. According to Underwood, fire exclusion has also resulted in trees like the eastern white pine and the red maple, trees that aren’t fire adapted, encroaching on the yellow pine’s range, taking space and resources from the yellow pines. As Grissino-Mayer says, “You take fire out, it changes the path that these forests develop, and we’re going to have different tree species, different plant species, different grass species, different everything.”
“Even today, [the forests] don’t look anything like they did in the 1800s,” Grissino-Mayer says. He talks particularly about rhododendrons and mountain laurel growing thickly in the understory. They’re beautiful plants, and they have beautiful flowers. “Guess what? Those shrubs are meant to burn,” he says. Regular fires keep shrubbery in check. After 80 years of fire exclusion, “the national park and national forest are just choked with it.” It’s not simply the number of shrubs. Without regular fires coming through and burning them, they grow much larger than they could before.
The fact that they’re growing larger is more of a problem than is immediately obvious. According to Grissino-Mayer, if a fire did start in the forest, the taller shrubs would act as ladder fuels: the fire could climb them to reach the canopy. So, even though we now understand the importance of fires, we can’t just let them burn. The Forest Service “knows what needs to be done, but their hands are tied by 80 years of mismanagement.”
Ladder fuels aren’t even the only problem. “You’ve got fuels that have been building up for eighty years,” he says. “I can go to Great Smoky Mountains National Park right now, and I can dig through all that, and not even hit soil.” If you have a gallon of gasoline, you can’t light just half of on fire; likewise, when some of this fuel catches fire, all of it will. “When it burns, it’s going to burn big time,” he says. These problems are massive obstacles to prescribed burns: you have to deal with the fuel to make sure the fire won’t get out of control, you have to take down the shrubs so the fire won’t climb to the canopy. It’s not simple.
But even more complicated are the sociopolitical problems. The biggest problem in this part of the Appalachians is wildland-urban interface, which is a fancy way of saying that our towns and cities are right next to our forests. “We have literally entire towns right up against the borders of the national parks,” says Grissino-Mayer. He lists cities like Gatlinburg and Pigeon Forge, towns like Townsend and Greenville. It’s impossible to do burns near them: the danger if the fire got loose is too great. Even worse is the smoke: “All the smoke that comes from these burns would wipe out several days or even a week’s worth of tourism in places like Gatlinburg.” Losing several days worth of tourism would be economically devastating. Burns have to be done in incredibly remote locations.
Even then there are problems. Great Smokey Mountains National Park has ten million visitors a year. It plays a huge part in the economies of Tennessee and North Carolina. Since it’s impossible for us to truly control a fire, Grissino-Mayer says that doing a prescribed burn risks burning down the majority of, or at least large swathes of the Park. Since a burned, dead park won’t attract ten million tourists a year, every prescribed burn risks tanking the economies of two states.
As a result, the Forest Service does few and small burns in Great Smokey Mountains National Park. Grissino-Mayer says there’s no way they can do burns as extensively and as often as would be necessary to return the forests to their previous state. No amount of intelligent management will be able to correct the blissfully ignorant mismanagement of the past. With the best of intentions, we excluded fire from the Smokies and irreparably altered the ecosystem. Despite our best intentions, we’ll never return the mountains to their former state.